Under new rules, introduced by the aviation regulator, carriers could be penalised by up to €3,000 for every time they fail to adhere to scheduled flight times.
The Commission for Aviation Regulation will also publish details of any future fines — a measure strongly opposed by some airlines.
In future, the regulator will have powers to impose a fine for each occasion where an aircraft operates at a time significantly different from its allocated slot following an initial warning after the first breach.
However, fines can only be issued after “a body of evidence” has built up which demonstrates that the breaches are repeated and intentional.
The regulator said airlines could currently only be issued with a once-off fine of €3,000 regardless of the number of breaches of slots.
“There is little incentive to change behaviour if an operator believes that it will be fined €3,000 regardless,” said a commission spokesperson.
The regulator claimed the new system of sanctions per incident were “proportionate and dissuasive”.
In the UK, Easyjet was fined over £1.1m (€1.3m) in the 2016/17 season over its failure to adhere to slot allocations.
ACL, the co-ordinator of slot allocations at Dublin Airport, welcomed the changes as it claimed the existing approach was not a sufficient deterrent against repeated or consistent abuse of slot operations.
The company said it has had to raise an increasing number of queries with airlines using Dublin Airport over their flight operations in recent years.
ACL said only one fine has been issued since Dublin Airport was designated as a slot-co-ordinated airport in 2007 in order to control an increase in flights especially at peak times.
ACL said the fine appeared to have no impact as the airline continued to subsequently fly outside allocated times.
An air carrier may not operate at a co-ordinated airport in the absence of a slot allocated by the airport co-ordinator.
The need for co-ordination of slots at Dublin has grown with the airport scheduled to exceed 30 million passengers this year.
At its busiest times, the airport is handling up to 47 takeoffs and landings per hour.
Many airlines including Aer Lingus and Cityjet have opposed the new fines’ system which is supported by the Irish Aviation Authority.
DAA, previously known as the Dublin Airport Authority, expressed concern that it would lead to excessive fines and urged the regulator to set an annual cap on the maximum amount an airline could be penalised.
However, the commission said that an annual cap was “not desirable nor appropriate.”
It also said that it would publish details of uncontested sanctions as it would provide an added incentive to airlines to comply with slot allocations.